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未来式火星降落实验

未来式火星降落实验

分类:科技Science   更新:2015/5/23   来源:history

未来式火星降落实验

    A US space agency (Nasa) experiment on Saturday to test future Mars landing technologies proved largely successful.
    美国宇航局上周六进行了一次未来式火星降落实验,结果大获成功。
    Artist's impression: A rocket motor was used to shoot the vehicle up through the stratosphere
    A flying saucer-shaped vehicle was sent high into the atmosphere via a balloon to trial a new type of parachute(降落伞) and an inflatable Kevlar ring that could help slow down a spacecraft as it approaches the Red Planet's surface.   All of the equipment appeared to work apart from the parachute, which failed to deploy1 fully2.   The experiment was sent up from Hawaii.   Nasa hopes the lessons learned will enable it put heavier payloads on Mars in the decades ahead.   The current limit is about one-and-a-half tonnes.   If humans are ever to go to the planet, this mass capability3 will have to rise to well beyond 10 tonnes.   Saturday's test vehicle, known as the Low Density4 Supersonic Decelerator (LDSD), ditched in the Pacific after its flight.   Teams were despatched to try to locate the demonstrator so that its data recorder could be recovered.   This will give engineers the most detailed5 information on what precisely6 happened during the experiment.   Video cameras on the ground and on the LDSD captured most of the flight.   The helium balloon was launched from the US Navy's Pacific Missile Range Facility in Kauai at just after 08:40 local time.    It took over two hours to raise the saucer-shaped vehicle to roughly 35km, whereupon it was released.   A rocket motor then kicked the LDSD on up through the stratosphere to above 50km, and to a velocity7 of Mach 4 (four times the speed of sound) - the sort of conditions a spacecraft approaching Mars might encounter.   As the vehicle began to slow, it deployed8 the first of its two new atmospheric9 braking systems.   This first system was a 6m inflatable "doughnut". It enlarged the LDSD's girth and so will have slowed the saucer further by increasing the amount of drag it experienced.   The second braking system, however, did not nete out properly.   Upward-looking video showed the 30m-diameter supersonic parachute failing to unfurl correctly.   Nasa engineers said before the test that they would gather valuable data whether the technologies on the LDSD worked properly or not.   The project hopes to return to Hawaii next year to conduct two further test flights.
    1 deploy      v.(军)散开成战斗队形,布置,展开 参考例句:
    The infantry began to deploy at dawn.步兵黎明时开始进入战斗位置。
    The president said he had no intention of deploying ground troops.总统称并不打算部署地面部队。
    2 fully      adv.完全地,全部地,彻底地;充分地 参考例句:
    The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
    They soon became fully integrated into the local netmunity.他们很快就完全融入了当地人的圈子。
    3 capability      n.能力;才能;(pl)可发展的能力或特性等 参考例句:
    She has the capability to benete a very fine actress.她有潜力成为杰出演员。
    Organizing a whole department is beyond his capability.组织整个部门是他能力以外的事。
    4 density      n.密集,密度,浓度 参考例句:
    The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
    The region has a very high population density.该地区的人口密度很高。
    5 detailed      adj.详细的,详尽的,极注意细节的,完全的 参考例句:
    He had made a detailed study of the terrain.他对地形作了缜密的研究。
    A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
    6 precisely      adv.恰好,正好,精确地,细致地 参考例句:
    It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
    The man adjusted very precisely.那个人调得很准。
    7 velocity      n.速度,速率 参考例句:
    Einstein's theory links energy with mass and velocity of light.爱因斯坦的理论把能量同质量和光速联系起来。
    The velocity of light is about 300000 kilometres per second.光速约为每秒300000公里。
    8 deployed      (尤指军事行动)使展开( deploy的过去式和过去分词 ); 施展; 部署; 有效地利用 参考例句:
    Tanks have been deployed all along the front line. 沿整个前线已部署了坦克。
    The artillery was deployed to bear on the fort. 火炮是对着那个碉堡部署的。
    9 atmospheric      adj.大气的,空气的;大气层的;大气所引起的 参考例句:
    Sea surface tempe

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